I recently just installed an aftermarket exhaust manifold on my evo 5. When I went for a spin to see how everything was the car seemed like it wasn't running much boost. I could hear the turbo spooling however it didn't pull as hard as it normally does. I checked the manifold and there is no visible leaks and nothing I can see that is done incorrectly. I do not have a boost gauge so I cant forsure say im not running standard boost. any suggestions would be much appreciated. Thanks.

 

gonna say the obvious here, boost leak test. also, get a boost gauge. I'm going to assume you are running higher than stock boost, why wouldn't you have one?